const gulp = require('gulp')
const concat = require('gulp-concat')
const clean=require('gulp-clean-css')
function fn(cb) {
    console.log(123);
    cb();
}

function css(cb) {
    gulp.src('./src/css/*.css')
        .pipe(concat('all.css'))
        .pipe(clean())
        .pipe(gulp.dest('./dist.css'))
    cb();//告诉gulp当前任务结束
}
module.exports.fn = fn;
module.exports.css = css;